Britannica Sources used in this answer

Why does the partial positive charge on carbon make organohalides chemically reactive?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

organohalogen compound Vinyl chloride is an organohalogen compound that has important industrial applications. When treated with certain catalysts, vinyl chloride monomers undergo polymerization and form the larger compound known as polyvinyl chloride, or PVC. PVC is used in the manufacture of numerous products, including packaging films and water pipes.

In organohalogen compounds, the chemical reactivity of alkyl halides is fundamentally linked to the polarity of the carbon-halogen bond. Because a halogen atom is more electronegative than carbon, it draws the shared bonding electrons toward itself.12

This electron displacement creates a partial positive charge ( $δ +$ ) on the carbon atom and a partial negative charge ( $δ -$ ) on the halogen. This partial positive charge makes the carbon atom an electrophilic site, meaning it is susceptible to attack by a nucleophile—a species with unshared electrons available for bond formation.13

During nucleophilic substitution, the nucleophile approaches the electron-deficient carbon, eventually leading to the breaking of the carbon-halogen bond as the halogen departs with both bonding electrons as a negatively charged ion. The ease of this process is heavily influenced by the strength of the carbon-halogen bond, with weaker bonds generally facilitating higher reactivity.31